The invention concerns a tool for completing the installation of a shaft-journalling bearing of the type in which an extended inner race is engaged by an eccentric locking collar for locking the bearing in position on the shaft and, more particularly, a tool for assembling the locking collar to such a bearing and applying a selected locking torque.
Mating an eccentrically cammed locking collar with a similarly cammed inner race of a bearing is a well known means for locking a bearing inner race to a shaft. Rotation of the locking collar relative to the inner race provides an initial clamping or locking action and further tightening occurs during operation due to the well known mechanical phenomenon of "rolling" or "creep", whereby a bearing inner race having a bore somewhat larger than the shaft and subjected to a one-directional load would rotate slower than the shaft if left free to do so. The sustained effort of the inner race to creep around the shaft while it is restrained by the locking collar tends to increase the clamping or locking force. (See, for example, U.S. Pat. No. 2,226,524 Runge, U.S. Pat. No. 2,584,740 Reynolds and U.S. Pat. No. 2,728,616 Potter).
In the conventional installation method, a preliminary manual assembly and hand-tightening of the locking collar onto the bearing is followed by a final tightening using a hammer and drift or a C-spanner. (The hammer and drift method is described in an instruction sheet, Form No. 512, of the Fafnir Bearing Division of Textron, Inc.) In either case, the tool engages a drive hole in the locking collar and "impacts" the collar so as to drive it more tightly onto the inner race. Disadvantages of these manual methods are the inevitable variations in the final torque applied and also the need to have sufficient space around the bearing installation to permit manipulation of the tools.
Bearings with self-locking collars are widely used on agricultural machines. A typical combine harvester, for example, may have more than fifty such bearings. When properly installed, they provide an efficient and cost-effective method of securing a bearing to a shaft.